An oxidation-reduction reaction, also called a redox reaction, is a chemical reaction where oxidation and reduction happen at the same time.
Key Ideas:
- Oxidation = loss of electrons or increase in oxidation number.
- Reduction = gain of electrons or decrease in oxidation number.
- These two processes are always linked → when one substance loses electrons, another must gain them.
Examples in everyday words:
- Rusting of iron → Iron atoms lose electrons (oxidation) while oxygen and water gain electrons (reduction).
- Respiration → Glucose is oxidized to release energy, while oxygen is reduced to water.
- Batteries → Chemicals inside undergo redox reactions to produce electric current.
- Combustion → Fuel is oxidized and oxygen is reduced, releasing heat and light.
Simple definition:
A redox reaction is a chemical process in which one substance is oxidized and another is reduced at the same time.